单项选择题
A．was big enough to hold all the citizens of the city B．was difficult because of the lack of detail C．was the most modem Opera House till then D．was built with the joint efforts of the country
A．the building could be the one in the world B．the building could be named after the winner's name C．the winner could benefit a lot from the designing and construction D．the winner could get much money from his investment
A．The volume of the atmosphere is four times that of the world's. B．The water in the oceans is the main source of rain and snow on land areas. C．The atmosphere is mainly composed of the vapor carded over land by air currents. D．The earth cannot support the water in the atmosphere if it falls down onto the earth suddenly.